It was however in the field of commercial vehicles that Mantelli found its specialization. In the thirties they produced among others the first bus and trailer, as well as numerous types of city buses and suburban.

During World War II the factories in Turin were completely destroyed and in 1950, the company would resume its activities, through the initiative of the sons and the father and founder, who rebuilt the factory from scratch.

Mantelli logo’s initially appeared on light trucks for specific uses, such as advertising “floats”, ambulances and funeral cars. Later the company also dedicated to cars, building a number of fabrics especially Fiat 600, Fiat 1100 and the new 500. To remember a remarkable two-seater spider style thirties on mechanical Fiat 1100/103. Among the latest achievements of the company was a Fiat 850 four-door, after which all activity was suspended.